1. Field of the Invention
The present invention relates to an optoelectronic interconnection board, an optoelectronic interconnection apparatus using the optoelectronic interconnection board, and a manufacturing method thereof, and more particularly to an optoelectronic interconnection board on which a semiconductor device is mounted with high alignment accuracy, an optoelectronic interconnection device using the optoelectronic interconnection board, and a manufacturing method thereof.
2. Description of the Related Art
The operating speed of large scale integrated circuits (LSIs) is increasing every year due to improvements in performance of electronic devices, e.g., field-effect or bipolar transistors constituting the LSI.
However, the operating speed on the level of a printed wiring board having an LSI mounted thereon is slower than the internal operating speed of the LSI, and the operating speed becomes slower on the level of a rack having the printed wiring board mounted thereon. Such a reduction in operating speed occurs due to an increase in, e.g., transmission loss and/or noise, or electromagnetic interference in electric interconnection lines outside the LSI which is caused by an increase in an operating speed of the LSI, i.e., an increase in operating frequency. Therefore, the operating speed of a longer interconnection line has to be reduced to avoid degradation in signal quality. In other words, even if the operating speed of the LSI as an active device is increased, the operating speed of a system is constrained to be decreased due to reduced operating speed in the electric interconnection lines outside the LSI by mounting on the board or rack. In recent years, there is an increasing tendency that the operating speed of the entire system is dominated by mounting technology rather than operating speed of the LSI.
With such a problem of an electric interconnection apparatus, an optical interconnection apparatus which optically connects LSIs with each other has been proposed. Characteristics of optical interconnection lie in that frequency dependence, e.g., of loss, is rarely present in a wide frequency range of 100 GHz or more from a direct current, and interconnection of several tens of Gbps is readily realized because of absence of electromagnetic interference or ground bounce noise in interconnection paths, and others.
Therefore, in the optical interconnection apparatus, operation at a very high speed can be expected even on the level of a printed wiring board or the level of a rack, and studies and development are actively underway. Among others, an optoelectronic interconnection apparatus using an optoelectronic interconnection board in which optical interconnection lines and electric interconnection lines are incorporated is disclosed in, e.g., Japanese Patent No. 3612243 or Y. Ishii, et al.; Proc. Electronic Components and Technology Conference, IEEE, p. 870, 2001.